var opacity = 0.9;
	
function hidemessage() {
	aktiv = window.setInterval("fading()", 100);
}

function fading() {
	opacity -= 0.1;

	a = document.getElementById('meldung').style;
	if(opacity <= 0) {
		// Werte zurücksetzen
		a.visibility="hidden"; 
		a.MozOpacity = 0.9;
		
		// Interval abbrechen
		window.clearInterval(aktiv);
	} else {
		a.MozOpacity = opacity;
	}
}